Image sensor, and image processing apparatus and information processing system using the same

ABSTRACT

This invention has as its object to provide an image sensor which can effectively attain higher read resolution, and an image processing apparatus and information processing system using the same. To achieve this object, function members including a light source ( 6 ) for irradiating an object to be read (PP) with light, a sensor ( 3 ) for receiving light reflected by the object to be read (PP), and an imaging element ( 7 ) for forming an image of the reflected light on a light-receiving portion of the sensor ( 3 ) are attached to and supported by a support member ( 1 ) to have a predetermined positional relationship. In order to assure high attachment positional precision and rigidity for the function members, the support member ( 1 ) is formed to have a hollow shape. The support member ( 1 ) is formed to have the hollow shape along its longitudinal direction. Two side portions of the support member ( 1 ) are formed to have a hollow shape, and are coupled at end portions in the longitudinal direction.

FIELD OF THE INVENTION

[0001] The present invention relates to an image sensor for readinglight reflected by a document surface to be read (object to be read)using a sensor, and an image processing apparatus and informationprocessing system using the same.

BACKGROUND OF THE INVENTION

[0002] Conventionally, an image sensor which has a sensor array forperforming photoelectric conversion, an imaging element for imaginglight coming from a document on the sensor array, and a light source forilluminating the document is known.

[0003]FIG. 12 is a schematic perspective view showing the outerappearance of the conventional image sensor. Referring to FIG. 12,reference numeral 1 denotes a frame as a support member; and 5, a topplate glass which can contact a document PP and serves as a transparentmember that specifies the read surface. Reference numeral 8 denotesspacers which contact the transparent member 5 to define the position ofthe sensor with respect to the read position. Most photosensors (pixels)line up in a main scan direction DM that agrees with the longitudinaldirection of the frame 1, the widthwise direction of which agrees with asub-scan direction DS.

[0004]FIG. 13 shows a section taken along a lone C-C′ in FIG. 12.Referring to FIG. 13, an imaging element 7 is set in a space D of theframe 1. A light source 6 is set in a space E. A sensor array 3 isarranged on an electric circuit board 4, and is set to face a space F.The spaces D, E, and F communicate with one another. Other spaces L andM are unfilled spaces which are formed upon forming the frame 1 by solidmolding to prevent sink marks.

[0005]FIG. 14 is a sectional view showing other unfilled spaces of theconventional image sensor. In FIG. 14, spaces N, Q, R, and S areunfilled spaces.

[0006] Such image sensor is assembled as follows. That is, the lightsource 6 is fixed to a mount surface G of the frame 1 by an adhesive orscrews, and the imaging element 7 is inserted into the space D and isfixed to a mount surface H of the frame 1 by an adhesive or screws.Then, the electric circuit board 4 provided with the sensor array 3 isfixed to a mount surface I of the frame 1 by an adhesive or screws.

[0007] However, in order to achieve still higher read resolution of theconventional image sensor, the following technical problems remainunsolved.

[0008] 1. The flatness precision of a document and the image sensor isimportant to realize higher read resolution. However, it is hard forconventional molding of the frame 1, which is formed to have an unfilledshape that forms large openings on its outer surface, to obtain a framethickness that can assure good molding balance with the flatness.Furthermore, since space L- and M-side blocks, which are partitioned bythe space D as the optical path of optical information coming from thedocument PP, suffer variations in frame thickness, such variations inthickness of the frame 1 cause molding shrinkage variations. For thesereasons, formation of a high-precision flat surface required for theframe 1 is limited, and it is difficult to form a high-precision flatsurface having flatness of 0.1 mm or less over the total length of theimage sensor in the main scan direction DM.

[0009] 2. In order to realize higher read resolution, the frame 1 musthave high rigidity so that it does not deform by a pressure T of apressing means which prevents the image sensor or document PP fromfloating. However, upon conventional molding of the frame 1 which isformed to have an unfilled shape that forms large openings on its outersurface, the openings readily collapse, and the rigidity obtained withthe frame 1 is limited.

SUMMARY OF THE INVENTION

[0010] The present invention has been made in consideration of the abovesituation, and has as its object to provide an image sensor which caneffectively attain higher read resolution, and an image processingapparatus and information processing system using the same.

[0011] In order to solve the aforementioned problems and to achieve theabove object, an image sensor according to the present invention ischaracterized by the following arrangement.

[0012] That is, an image sensor in which function members including alight source for irradiating an object to be read with light, a sensorfor receiving light reflected by the object to be read, and an imagingelement for forming an image of the reflected light on a light-receivingportion of the sensor are attached to and supported by a support memberto have a predetermined positional relationship, is characterized inthat the support member is formed to have a hollow shape.

[0013] An image processing apparatus of the present invention ischaracterized by reading and processing image information from an objectto be read using the image sensor.

[0014] An information processing system of the present invention ischaracterized by comprising the image processing apparatus, and anexternal information processing apparatus for controlling the imageprocessing apparatus.

[0015] According to the present invention, the unfilled shape of theframe is formed to have a hollow shape. As a result, it becomes easierto obtain the frame thickness which can assure good molding balance withflatness, and a frame with high-precision flatness, which is free fromany influences of shrinkage upon frame molding can be formed.

[0016] Since the need for forming openings of the unfilled shape can beobviated, the frame never collapses at its openings, and the framerigidity can be improved.

[0017] Furthermore, since no complicated unfilled shape need be adopted,simple metal molds can be used, which are advantageous for metal moldcost and metal mold service life.

[0018] Since the image sensor can have a flat outer surface, good outerappearance can be assured, and such sensor is easy to handle.

[0019] In this manner, a frame having high-precision flatness and highrigidity which can effectively achieve higher read resolution of theimage sensor can be formed.

[0020] Other objects and advantages besides those discussed above shallbe apparent to those skilled in the art from the description of apreferred embodiment of the invention which follows. In the description,reference is made to accompanying drawings, which form a part hereof,and which illustrate an example of the invention. Such example, however,is not exhaustive of the various embodiments of the invention, andtherefore reference is made to the claims which follow the descriptionfor determining the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic perspective view of an image sensoraccording to the present invention;

[0022]FIG. 2 is a sectional view taken along a line A-A′ in FIG. 1;

[0023]FIGS. 3A and 3B are sectional views showing gas assist moldingused to form a hollow unfilled portion;

[0024]FIGS. 4A and 4B are sectional views showing gas assist moldingused to form a hollow unfilled portion;

[0025]FIGS. 5A and 5B are sectional views showing gas assist moldingused to form a hollow unfilled portion;

[0026]FIGS. 6A and 6B are sectional views showing gas assist moldingused to form a hollow unfilled portion;

[0027]FIG. 7 is a schematic sectional view of an image informationprocessing apparatus using a flatbed type image sensor according to anembodiment of the present invention;

[0028]FIG. 8 is a schematic perspective view of a sheet-feeder typeimage sensor according to the second embodiment of the presentinvention;

[0029]FIG. 9 is a sectional view taken along a line B-B′ in FIG. 8;

[0030]FIG. 10 is a schematic sectional view of an image informationprocessing apparatus using a sheet-feeder type image sensor according toan embodiment of the present invention;

[0031]FIG. 11 is a block diagram for explaining an informationprocessing system according to an embodiment of the present invention;

[0032]FIG. 12 is a schematic perspective view of a conventional imagesensor;

[0033]FIG. 13 is a sectional view taken along a line C-C′ in FIG. 12;and

[0034]FIG. 14 is a sectional view of another prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Preferred embodiments of an image sensor according to the presentinvention will be described hereinafter with reference to theaccompanying drawings. Note that the same reference numerals denotesubstantially the same members as those in the conventional structure,and a description thereof will be omitted.

[0036]FIG. 1, FIG. 2, and FIGS. 3A to 6B best illustrate the feature ofthe present invention. FIG. 1 is a schematic perspective view showingthe outer appearance of an image sensor. FIG. 2 is a sectional viewtaken along a line A-A′ in FIG. 1. FIGS. 3A to 6B are sectional viewsshowing gas assist molding used to form a hollow unfilled portion.

[0037] Referring to FIG. 2, a frame 1 (support member) is formed to havehollow spaces J and K. Such hollow unfilled spaces can be formed by gasassist molding. In FIG. 1, reference numeral 2 denotes molding gates forgas assist molding, which also serve as gas injection holes.

[0038] A method of forming the frame 1 by gas assist molding will beexplained below.

[0039]FIGS. 3A and 3B show the state of metal molds before molding,FIGS. 4A and 4B show the state of the metal molds upon completion ofresin injection, FIGS. 5A and 5B show the states of the metal molds andframe 1 upon completion of gas injection, and FIGS. 6A and 6B show thestate of the completed hollow frame 1. In each pair of figures, B showsthe A-A′ section of A, and A shows the U-U′ section of B.

[0040] In FIGS. 3A and 3B, reference numeral 2 denotes molding gateswhich also serve as glass injection holes, and are formed on one endface of the frame 1 in the longitudinal direction DM. On the oppositeend face, residual resin vent holes 11 for exhausting residual moldingresin are formed, and residual resin relieve sections 12 are spaces forstoring residual molding resin.

[0041] In FIGS. 4A and 4B, reference numeral 13 denotes molding resinwhich forms the frame 1. In FIGS. 5A and 5B, reference numeral 14denotes gas for forming hollow spaces in the molding resin.

[0042] The frame 1 is formed in the following procedure by gas assistmolding.

[0043] The molding resin 13 is injected into the metal molds shown inFIGS. 3A and 3B via the molding gates 2. The amount of resin to beinjected is (amount required to form the frame 1)+(resin amountcorresponding to residual resin). Then, gas is injected from the gasinjection holes 2. The amount of gas to be injected is large enough torelieve residual resin into the residual resin relieve sections 12 viathe residual resin vent holes 11. As shown in FIGS. 6A and 6B, aftermolding, the frame 1 is removed from the metal molds, and the moldinggates 2 and residual resin vent holes 11 are cut, thus completing theframe 1.

[0044] The frame 1 is divided into space J- and K-side blocks by a spaceD serving as the optical path of optical information coming from adocument PP, and the space J- and K-side blocks are formed to have ahollow shape with a frame thickness which can assure good moldingbalance with flatness. With this structure, the following effects areobtained.

[0045] (1) Since each of the space J- and K-side blocks is formed tohave a hollow shape with a frame thickness which can assure good moldingbalance with flatness, high-precision flatness can be obtained by eachblock. The frame 1 obtained by coupling two end portions of the space J-and K-side blocks having high-precision flatness can have high-precisionflatness.

[0046] (2) Since the space J- and K-side blocks are formed to have ahollow shape having no openings on the outer surface of the frame 1unlike the unfilled space formed by conventional solid molding, theframe 1 never collapses at the openings, and the rigidity of the framecan be improved.

[0047] (3) Since no complicated unfilled shape need be adopted, simplemetal molds can be used, which are advantageous for metal mold cost andmetal mold service life.

[0048] (4) Since the image sensor can have a flat outer surface, goodouter appearance can be assured, and such sensor is easy to handle.

[0049]FIG. 7 shows an example of a scanner as an image informationprocessing apparatus which uses a flatbed type image sensor unit of thisembodiment. Referring to FIG. 7, reference numeral 5 denotes atransparent member which can contact a document PP and defines the readsurface; 8, a spacer which contacts the transparent member 5 to definethe position of the sensor with respect to the read position; 201, ascan belt serving as a feed means which carries a sensor unit and scansit in a scan direction DS; 202, feed rollers for driving the scan belt;and 230, a system control board as a control means, which has acontroller for controlling respective units, a driving circuit for aphotoelectric conversion element, an image information processor, atransmitter, and the like. Reference numeral 240 denotes a power supplyof the apparatus.

[0050] In this image information processing apparatus, an image sensorunit 200 moves in the scan direction DS with respect to a document PPplaced on the transparent member 5. Upon reading image information ofthe document PP by this scan, since the frame 1 has high-precisionflatness and high rigidity, as described, image information can be readat high read resolution.

[0051]FIGS. 8 and 9 show the second embodiment of the present invention,i.e., a sheet-feeder type image sensor. FIG. 8 is a schematicperspective view showing the outer appearance of the image sensor, andFIG. 9 is a sectional view taken along a line B-B′ in FIG. 8.

[0052] Referring to FIG. 8, reference numeral 10 denotes a transparentmember which is attached to the frame 1 at a position where it cancontact a document PP. Reference numeral 9 denotes a roller forconveying the document PP. In FIG. 9, the frame 1 is formed to havehollow spaces J and K.

[0053] With this arrangement, the same effects as in the firstembodiment can be obtained for the sheet-feeder type image sensor.

[0054]FIG. 10 shows an example of a facsimile apparatus having acommunication function as an image information processing apparatuswhich uses a sheet-feeder type image sensor unit 100 according to thesecond embodiment of the present invention. Referring to FIG. 10,reference numeral 102 denotes a feed roller as a feed means for feedinga document PP toward the read position; and 104, a separation piece usedto reliably separate and feed documents PP one by one.

[0055] Reference numeral 106 denotes a platen roller as a convey means,which is provided at the read position with respect to the sensor unitto regulate the surface to be read of the document PP and to convey thedocument PP. Reference symbol P denotes a print medium which is rollpaper in FIG. 10. Image information read by the sensor unit orexternally received image information in case of the facsimile apparatusor the like is formed on the medium P. Reference numeral 110 denotes aprint head as a print means for forming an image; and 112 a platenroller as a convey means which conveys the print medium P to the printposition of the print head 110 and regulates the surface to be printedof the print medium P.

[0056] Reference numeral 120 denotes an operation panel serving asinput/output means which has switches for making operation inputs, adisplay for displaying apparatus status messages and the like, and thelike. Reference numeral 130 denotes a system control board as a controlmeans which has a controller for controlling respective units, a drivingcircuit for a photoelectric conversion element, an image informationprocessor, a transceiver, and the like. Reference numeral 140 denotes apower supply of the apparatus.

[0057] In this the image information processing apparatus as well, uponreading image information on a document PP by moving the document PP,which is placed on the transparent member 10, in the scan direction DSof the image sensor unit 100, since the frame 1 has high-precisionflatness and high rigidity, as described above, image information can beread at high read resolution.

[0058]FIG. 11 shows an example of an information processing system usingthe image sensor described in the above embodiments. An example of thearrangement of a system which is built by connecting an image readingapparatus 70 that incorporates an image sensor 72 to a personal computer80, and outputs read image information to the computer or a network willbe explained below.

[0059] Referring to FIG. 11, reference numeral 71 denotes a CPU as afirst control means for controlling the overall image reading apparatus70; 72, an image sensor as a reading unit which comprises the lightsource, sensor, and the like, as described above, and converts adocument image into an image signal; and 73, an analog signal processingcircuit for executing an analog process such as gain adjustment or thelike of an analog image signal output from the image sensor.

[0060] Reference numeral 74 denotes an A/D converter for converting theoutput from the analog signal processing circuit 73 into a digitalsignal; 75, an image processing circuit for executing image processessuch as shading correction, gamma conversion, a zoom process, and thelike of the output data from the A/D converter 74 using a memory 76; and77, an interface for externally outputting digital image data that hasundergone the image processes of the image processing circuit 75.

[0061] The interface 77 complies with specifications such as SCSI,Bi-Centronics, or the like, which is normally used in a personalcomputer, and is connected to the personal computer 80. The analogsignal processing circuit 73, A/D converter 74, image processing circuit75, and memory 76 construct a signal processing means.

[0062] The personal computer 80 as a second control means has amagnetooptical disk drive, floppy disk drive, or the like as an externalstorage device or auxiliary storage device 81. Furthermore, in FIG. 11,reference numeral 82 denotes a display for displaying processes on thepersonal computer 80; and 83, a mouse/keyboard used to input commands orthe like to the personal computer. Reference numeral 84 denotes aninterface for controlling exchange of data, commands, and statusinformation of the image reading apparatus between the personal computerand image reading apparatus.

[0063] The personal computer 80 can input a read instruction to theimage reading apparatus via the mouse/keyboard 83. When a readinstruction is input by the muse/keyboard 83, the CPU 85 sends a readcommand to the image reading apparatus via the interface 84. Thepersonal computer 80 then controls the image reading apparatus inaccordance with control program information stored in a ROM 86. Notethat the control program may be loaded, into the personal computer 80,from a storage medium such as a magnetooptical disk, floppy disk, or thelike, which is loaded into the auxiliary storage device 81 and storesthe program, and may be executed by the CPU 85.

[0064] As described above, according to the above embodiments, since asupport member which is a key to determine the attachment positions offunction members that form an image sensor has a hollow shape, a moldingthickness which can assure good balance with flatness can be formed,thus obtaining a support member with a high-precision flat surface.

[0065] Since the need for forming large openings for an unfilled shapeon the outer surface of a support member can be obviated, the supportmember never collapses at the openings, and the rigidity of the supportmember can be improved.

[0066] Since no complicated unfilled shape need be adopted, simple metalmolds can be used, which are advantageous for metal mold cost and metalmold service life.

[0067] Since the image sensor can have a flat outer surface, good outerappearance can be assured, and such sensor is easy to handle.

[0068] The present invention is not limited to the above embodiments andvarious changes and modifications can be made within the spirit andscope of the present invention. Therefore, to apprise the public of thescope of the present invention the following claims are made.

What is claimed is:
 1. An image sensor in which function membersincluding a light source for irradiating an object to be read withlight, a sensor for receiving light reflected by the object to be read,and an imaging element for forming an image of the reflected light on alight-receiving portion of the sensor are attached to and supported by asupport member to have a predetermined positional relationship, whereinthe support member is formed to have a hollow shape.
 2. The sensoraccording to claim 1, wherein the support member is formed to have thehollow shape except for storage spaces for the function members.
 3. Thesensor according to claim l, wherein the support member is formed tohave the hollow shape along a longitudinal direction thereof.
 4. Thesensor according to claim 3, wherein two side portions of the supportmember are formed to have a hollow shape, and are coupled at endportions in the longitudinal direction of the support member.
 5. Thesensor according to claim 1, wherein no openings are formed on two outersurfaces of the support member.
 6. The sensor according to claim 1,wherein the support member is formed to have the hollow shape by gasassist molding.
 7. The sensor according to claim 6, wherein a gasinjection hole and resin injection hole in the gas assist molding areidentical to each other.
 8. The sensor according to claim 6, wherein agas exhaust hole and resin exhaust hole in the gas assist molding areidentical to each other.
 9. The sensor according to claim 6, wherein gasand resin injection holes, and gas and resin exhaust holes in the gasassist molding are respectively formed on opposing surfaces of thesupport member.
 10. An image processing apparatus for reading andprocessing image information from an object to be read using an imagesensor according to claim
 1. 11. The apparatus according to claim 10,wherein a flatbed type image sensor unit is used.
 12. The apparatusaccording to claim 10, wherein a sheet-feeder type image sensor unit isused.
 13. The apparatus according to claim 10, comprising driving meansfor changing a relative position between the image sensor and the objectto be read.
 14. An information processing system comprising an imageprocessing apparatus according to claim 10, and an external informationprocessing apparatus for controlling the image processing apparatus.